Certain Lewis acid catalysts, such as ferric chloride, dispersed in an oil such as rosin oil or linseed oil, have been used to promote the gelation of tung oil. The gelled tung oil can then be molded to form various articles, such as flooring tiles, as taught by C. Ellis in The Chemistry of Synthetic Resins, Chapter 61, p. 1218 (1935). Catalyzed tung oil compositions of this type, have also been used as fillers for metal articles, especially electromagnets. The compositions are, however, subject to inactivation in the presence of moisture, either from the atmosphere, or water tied up in the rosin or linseed dispersing oil. As a result, the manufacture of these compositions has been limited to low humidity days, so that the catalyst will be relatively water free and active when added to gel the tung oil. Such production methods are commercially inconvenient, and so there is a need for an additive which will counter the effect of water on the composition.